G'day,
In my view the key to winning the prize is building the smallest rover possible. Can a rover be built of say, 5kg or less? Because if you can then there may not be a need for expensive boosters, the spacecraft can be taken up piggy back on a geostationary launch, the extra delta V to get to the moon is minimal. Remember Asiasat 3? The interplanetary super highway can also be used. I have blogged on this topic with more detail on the link below. Your comments would be appreciated.

The weights of the Surveyors were between 900 kg and 1100 kg - at the beginning of the sixties of the past century. That was the weight at launch - the weight that arrived on the lunar surface was between 200 kg and 300 kg.

So to land a weight of 200 kg to 300kg on the Moon a weight of engine plus fuel/oxidizer of 600 kg to 900 kg was required.

Since now - four decades later - lightweight materials and solutions are available it may be possible that engine plus fuel/oxidizer plus rover and its ramp weigh 500 kg to 750 kg in total.

Why does the rover have to mass anywhere near that amount? The Mars Pathfinder was about 11kg. The only instrument this robot has to carry is an HD TV camera. Frankly, I expect the rover to mass 5 kg or less. There will be a requirement for a lander but even there the mass can be kept low. Remember the balloon cushions uses on the Mars rovers? A lunar version should work.

Have a look at this article on a 1kg military rover to see what can be done.

The weights of the Surveyors were between 900 kg and 1100 kg - at the beginning of the sixties of the past century. That was the weight at launch - the weight that arrived on the lunar surface was between 200 kg and 300 kg.

So to land a weight of 200 kg to 300kg on the Moon a weight of engine plus fuel/oxidizer of 600 kg to 900 kg was required.

Since now - four decades later - lightweight materials and solutions are available it may be possible that engine plus fuel/oxidizer plus rover and its ramp weigh 500 kg to 750 kg in total.

Because I mentioned Surveyor and also started a thread about inflatable rovers I was looking for the weights of former lunar rovers.

According to www.astronautix.com the Lunokhod weighed 840 kg - which seems to be too much to win the Google Lunar XPRIZE - while the manned lunar rovers the crews of Apollo 15 etc. used weighed 208 kg only.

Next imagine the seats removed, smaller wheels, manual steer removed, no storage for samples, no scientific equipments,... - then a Google Lunar XPRIZE-rover already will weigh less than NASA's former lunar rover. This seems to mean that it easyly can weigh less than Surveyor also.

Additionally think of the fact that a nromal digicam can be as small or slim as a pen today - thus weigh a few grams only.

The interesting point might be if an antena - even a parabol-antenna - can be made lightweight by using extremely thin and thus inflatable materials.

With modern electronics it should be no problem at all to make a remote controlled lunar rover with a very good camera than weighs only 10 or 20 kg. The only hard part will be getting it to the Moon

This is the way I see it, the rover is really the easiest part of the mission. The moon is so close you can use direct radio control and just deal with a few seconds of lag, the HD cameras and radio transceivers are all off-the-shelf deals. Really the only hard part is bundling it all up and 'space proofing' it. I don't really see a reason why you couldn't just build most of the sensitive electronics into an insulated and pressuised (with nitrogen to eliminate corrosion problems perhaps) box, which would get rid of a lot of the thermal transfer problems you get operating in a vacuum.

The real hard part is getting the lander from LEO to the moon surface, which means a kick and orbiting stage that can restart after days and remain on-trajectory for very long periods and a lander which will start and work flawlessly in space.

I reckon you could make the rover for less than $10000 but the kick and lander stages are what really puts the hurt on your pocket.

The numbers I personally posted were meant to show that the stages you are talking about will not weigh as much as they did in the case of Surveyor. And this will reduce the problem a bit because it increases the cahnces to get a rover weighing no more but mor likely less than the payload weight-capacity of a Falcon 1 - and perhaps of a QuickReach also.

You might be able to use Orbital science's pegasus launcher to get 400kg to LEO which should be enough payload for a rover, small kick stage and lander.

I think the launch cost is more than for a Falcon 1 but OS might give a discount to show their launcher could be used for lunar exploration and at least try to grab some of the market. They might even enter a team themselves to get into this area of commercial space.

_________________A journey of a thousand miles begins with a single step.

Why pay a lot more ($20 million I hear) for half the payload? Just use Falcon 1!

I did say that Orbital might decide to throw their hat in the ring themselves or they might be willing to give a large discount to be seen as a lunar player.

Also there may be reasons other than money for using Pegasus over Falcon 1 such as reliability and availability. Alternatively Pegasus may have improved performance/lower launch costs Once Falcon stars to take its customers. Still I agree $20m seems a bit high at the moment but you should not assume that the price wont go down in the future.

_________________A journey of a thousand miles begins with a single step.

in the case of SpaceX the likelihood of price reductions is more than 95% because Elon Musk has said that the present prices don't account for reusability.

Air Launch LLC's QuickReach is a competitor for SpaceX's Falcon 1 - even by price. So there will be market competition in the nearby future because QuickReach will be ready nect year or 2009 - this is an incentive for SpaceX to reduce prices to avoid losing actual or potential customers to Air Launch LLC.

SpaceX nonethless want to get as much customers as possible to become a market leader.

So there a several points why they really will want to reduce the prices once they can account for reusability. This of course doesn't mean that they will reduce the prices to the point where no profit is left - but they will avoid extraordinary profit rates exceeding 30%. Else they would have to fear new competitors and their rockets only can be applied in the launch and flight market.